Conventional toilets have a rim around the perimeter of the toilet bowl in order to flush the toilet. Such toilets are difficult to clean due to the overhanging rim that protrudes into the toilet bowl space. Rim toilets also have many orifices in order to rinse and flush the toilet. These orifices are easy targets for bacterial growth and frequently stain. Rimless toilets are currently available which boast easier cleaning and more effective flushing. However, even these rimless toilets have orifices in the toilet bowl which are prone to staining from iron or sediment deposits from water used in the toilet. A large rim also adds thickness to the toilet bowl, thus reducing the open area for capturing urine from standing urination and increasing the frequency with which urine is sprayed or splashed onto the toilet rim.
Rim rinsing requires large amounts of water to rinse excrement adhered to the bowl, and is often ineffective in that goal. In addition, rim rinsing requires the bowl to have a non-steep bowl wall so that rim rinse water can more effectively clean the bowl, and non-steep bowl walls are a primary cause and location for streaks or so called “skid marks” caused by excrement. Rim rinse water detracts from the amount of water per flush that can be used for the flushing jet, which creates many engineering design constraints for a toilet that lead modern low flush volume toilets to have narrower or longer trapways that are more easily clogged. Rim rinse water is often not separate from flush water. Thus, rim rinsing requires disinfecting or cleaning agents to either be used in all rinse and flush water. Otherwise, disinfecting or cleaning agents must be applied to the toilet manually by external means.
In addition, there are situations in which it is desirable to temporarily preserve the microbes in a user's excrement. In one example, it may be desirable to collect a sample to be analyzed for medical purposes as may be done when the toilet is a medical toilet. The medical toilet may include instruments to perform measurements related to a user's health. Another example is when the excrement is transferred to a digester for use in producing clean energy. In this example, it is desirable for the microbes to be alive when the excrement reaches the digester. After flushing, it is then desirable to kill microbes remaining in the toilet bowl and on exterior surfaces of the toilet.
What is needed is a toilet without a rim at all in order to decrease bowl thickness and increase the area for capturing human waste. Furthermore, what is needed is a means of separating rinse water from flush water, so that disinfecting or cleaning agents may be used at a minimum, which is ecologically preferred, material saving, and more energy efficient. In addition, what is needed is a toilet utilizing bowl and trapway designs which minimize the likelihood of streaks or stains and clogs respectively. Ideally, such improvements in a toilet would increase toilet cleanliness, reduce cleaning frequency, and possess antimicrobial properties which are actuated in a controlled manner.